Time to replace synchro. Anyone done there own

I have a kink in my 3rd gear and I think it's time to put new synchro in my tranny. I've done a lot of research and the Honda game guys were telling me to hold it in my 3rd gear before entering 3rd gear and rev for 2 mins and let it grind off until I am satisfied with it going into 3rd gear smoothly. Some people had also recommended Gm synchromesh transmission fluid. People swear by these methods that I should be able to go right into 3rd gear like " butter ". I have decided that the best thing to do is replace my 3rd gear synchro. I've called my local Acura dealership And they were not able to give me a quote on just 3rd gear synchro but all the synchros for about $500. Has anyone replaced their synchros before and maybe have part numbers and price for separate gear synchros.

Taking out the gearbox is a big job, so I would not hesitate to change all wearing items in the box and inspect the clutch to change at east the plates if needed. I did the synchro job this winter (I took the gearbox out and my Honda mechanics opened it to change the 2nd, 3rd and 4th synchros). It is not over difficult. Just time consuming. I changed the following items :


91121-PR8-008 BEARING, TAPER (55X90X23) (NTN)

91122-PR8-008 BEARING, SPECIAL TAPER (45X75X24)

91003-PR8-008 BEARING, SPECIAL BALL (34X68X20)

91002-PR8-008 BEARING, BALL (63/32)

91103-PR8-018 BEARING, NEEDLE (44X72X23)

91102-PR8-018 BEARING, NEEDLE (34X68.2X22)

91004-PR8-008 BEARING, ANGULAR (31X82X22)

90201-PR8-000 NUT, L. HEX. (32MM)

90602-PR8-000 RING, SNAP (68MM)

23621-PR8-010 SLEEVE SET HUB (3-4)

23651-PR8-000 SPRING, SYNCHRONIZER (78)

23646-PR8-020 SYNCHRONIZER SET (79)

23651-PG1-000 SPRING, SYNCHRONIZER (66) x2

23641-PR8-911 RING, BLOCKING (66SS) x2

91207-PR8-005 OIL SEAL (42X63X9)

91206-PR8-005 OIL SEAL (40X68X9)

91216-PR8-005 OIL SEAL (32X46X7)

Not particularly difficult but you'll need some special tools like a gear puller to take everything apart.

Just gotta take your time and not loose anything/get it mixed up.

Thanks [MENTION=12617]asylum[/MENTION] for the info. This really helped

Neumoney said:

I've done a lot of research and the Honda game guys were telling me to hold it in my 3rd gear before entering 3rd gear and rev for 2 mins and let it grind off until I am satisfied with it going into 3rd gear smoothly.

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I don't know what this means exactly but I wouldn't try it. You're not going to 'grind off' anything to make the synchros start working.

As was mentioned you should replace all synchros and seals while you're already in there. I just rebuilt my race car's Prelude tranny and it was really easy to open up and pop in new synchros (and a Quaife LSD) If the NSX trans is anything like the Accord/Prelude trans it will be pretty easy.

I've rebuilt a B-series transmission before, basically the same thing but cheaper with better aftermarket support.

The actual work on the transmission itself isn't too bad, you just need to be very careful to keep things clean and organized. While it's apart you might as well replace all the synchros, bearings, and seals as has already been mentioned, also if you want a better differential do that as well. When putting it back together you need to be super careful to clean the mating surfaces perfectly before applying Hondabond RTV. I find that it works best to smear a thin layer on both surfaces with a gloved finger then put them together.

Taking the gearbox out is easier than working on the gearbox internals. But if you have the balls to start it here you go: http://www.nsxcb.co.uk/showthread.php?14344-My-gearbox-revision-thread
There are several pitfalls while completing the gearbox.